TABLE 1

Population Characteristics at the Ages of 8, 12, and 16 Years

PretermTerm
8 y12 y16 y8 y12 y16 y
n seen/n eligible375/440374/440334/43747/53111/119102/124
Follow-up rate, %858576899383
Child characteristics
    Gestational age, mean (SD), wk28 (2)28 (2)28 (2)
    Birth weight, mean (SD), g961 (174)962 (174)960 (173)
    Male gender, n (%)200 (53)202 (54)177 (53)22 (47)51 (46)49 (48)
    Small for gestational age, n (%)89 (24)93 (25)77 (23)
    Multiple births, n (%)74 (20)76 (20)69 (21)
    Antenatal steroids, n (%)126 (34)129 (34)113 (34)
    O2 need at 28 d
        N374373333
        n (%)166 (44)171 (46)154 (46)
    Severe brain injury
        N371370331
        n (%)a35 (9)34 (9)31 (9)
Family factors
    Maternal education (N = 368), n (%)
        Less than high school48 (13)41(11)41 (12)7 (15)9 (8)5 (5)
        High school132 (36)131 (35)109 (33)8 (17)27 (24)27 (26)
        ≥1 y of college188 (51)201 (54)184 (55)32 (68)75 (68)70 (69)
    N3283293334298
        Race and ethnicity
            Non-Hispanic white, n (%)225 (69)225 (68)226 (68)29 (69)69 (71)72 (70)
            Black, n (%)57 (17)58 (18)60 (18)57(17)18 (18)19 (19)
            Hispanic white, n (%)16 (5)17 (5)17 (5)1 (2)2 (2)2 (2)
            Other, n (%)30 (9)29 (9)30 (9)5 (12)9 (9)9 (9)
    Single-parent household
        N36936944
        n (%)120 (33)125 (33)111 (33)11 (25)31 (28)25 (25)
Neurocognitive outcomes
    Any NSI
        N3713334698
        n (%)b57 (15)56 (15)51 (15)0 (0)0 (0)0 (0)
    WISC-III full-scale IQ
        N37336632699
        Mean (SD)91 (20)88 (18)87 (19)106 (16)104 (16)104 (16)
  • The number of children (n) for whom data are available is mentioned only when there are missing data.

  • a Severe brain injury includes grades 3 to 4 intraventricular hemorrhage, periventricular leukomalacia, and grade 2 and above ventriculomegaly on neonatal ultrasound.

  • b NSI includes the presence of any of the following: abnormal neurologic examination, including cerebral palsy, ventriculo peritoneal shunt, seizure disorder, hearing aids, and services for the blind.